Cobalt ii halide hydrazine complexes

ABSTRACT

COBALT (II) HALIDE TRIHYDRAZINATES OF THE FORMULA   (CO(II) (R-NH-NH2)3)X2   ARE PREPARED AS WELL AS COBALT (II) HALIDE TRIS(HYDRAZINE HYDROCHLORIDE) COMPLEXES OF THE FORMULA   (CO(II)(N2H4HX)3)X2   WHERE R IS H, ALKYL, ARYL, HALOARYL AND X IS HALOGEN. THE COMPOUNDS ARE USEFUL AS DRIERS FOR ALKYL RESINS AND TO ACCELERATE THE OXIDATIVE POLYMERIZATION OF OLEFINIC POLYMER SYSTEMS, PARTICULARLY UNSATURATED POLYESTERS, IN CONJUNCTION WITH ORGANIC PEROXIDES AND AS PROMOTERS FOR KETONE ALDOL CONDENSATION. KNOWN CO II COMPLEXES OF THE FORMULA (CO(II)R-NH-NH2)2)X2 ALSO HAVE THESE SAME USES.

United States Patent Oflice 3,728,087 COBALT II HALIDE HYDRAZINE COMPLEXES Christian H. Stapfer, Newtown, and Richard W. DAndrea, New Hope, Pa., assignors to Cincinnati Milacron Chemicals, Inc., Reading, Ohio No Drawing. Filed Apr. 6, 1970, Ser. No. 26,161 The portion of the term of the patent subsequent to Mar. 14, 1989, has been disclaimed Int. Cl. C0111 21/00; C01c N US. Cl. 423-413 15 Claims ABSTRACT OF THE DISCLOSURE Cobalt (II) halide trihydrazinates of the formula [Co(II) (RNHNHz)3]X are prepared as well as cobalt (II) halide tris(hydrazine hydrochloride) complexes of the formula where R is H, alkyl, aryl, haloaryl and X is halogen. The compounds are useful as driers for alkyl resins and to accelerate the oxidative polymerization of olefinic polymer systems, particularly unsaturated polyesters, in conjunction with organic peroxides and as promoters for ketone aldol condensation. Known Co III complexes of the formula [Co (II) (R-NHNH ]X also have these same uses.

This invention relates to novel cobalt complexes and their use in drying alkyl coating compositions, autoxidation of olefinic materials and in ketone aldol condensations.

Hydrazines are known to form stable coordination complexes, or chelates, with transition metals. With cobaltous halides they form 2 to 1 complexes known as the dihydrazinates which are described in the literature. Hydrazine itself reacts readily with cobalt (II) chloride, for instance to form the dihydrazinate complex:

and under certain conditions, the unstable hexahydrazinate [Co(II) (N H ]Cl can be formed in which the hydrazine acts as a unidentate ligand.

The term paint is used herein to include oil-based paint, water-based and organic-based varnishes, lacquers and similar coating compositions which may be clear, pigmented, or contain dyes.

The curing or drying of coating compositions such as alkyd paint formulations is frequently catalyzed by various metal salts. Cobalt soaps are especially preferred as paint dryers because they most actively promote the formation of free radicals at loci of unsaturation in films of coatings and paint. The production of these free radicals catalyze an autoxidation process resulting in actual crosslinking within the film. However, cobalt salts have had several disadvantages prior to our invention. In addition to high cost, cobalt salts cause extensive wrinkling in paint films when used in amounts necessary to produce commercially desirable drying times. It has been usually necessary to replace a portion of the cobalt salt with a salt of a less expensive metal because of the high cost and in order to prevent wrinkling, the replacement of the amount of cobalt salt necessary to prevent wrinkling results in a substantial increase in the time required for drying. Attempts have been made to accelerate the drying of alkyl paints by including compounds such as 1,10- phenanthroline, 2,2 bipyridine or 8 hydroxyquinoline. While these accelerators have been used for cobalt and manganese drying catalysts, they have not attained significant commercial importance. Although they may be 3,728,087 Patented Apr. 17, 1973 good accelerators, these compounds are far too expensive to be used in the necessary amounts and also promote discoloration of the paint film. For example, 1,10-phenanthroline cannot be used in quantities exceeding 0.05 weight percent of the paint because higher concentrations cause the paint film to yellow and when used in levels of 0.05 weight percent, the acceleration of drying time is not sufiicient to otf-set the increase in cost.

Hydrazines have also been proposed as activators in drying alkyd paints but they cause extreme discoloration (yellowing), surface wrinkling and deterioration. Moreover, they are not as active as would be desired.

It is also well known that the crosslinking polymerization of olefinic polymers such as styrene or butadienc modified polyester resins proceed by oxygen transfer using organic peroxides as a source of free radical and the same cobalt carboxylates as above :as cocatalysts. Although cobalt soaps are the preferred cocatalysts for the polymerization of these resins, mainly because they allow good curing characteristics and dimensional stability, the time span in which they cause the polymeric resin to gel is long and, should one want to reduce said time span ,by

increasing the amount of cobalt, they have a tendency to severely discolor the resin.

Furthermore, in various applications where the polyester resin formulation contains water, cobalt carboxylates are altogether inadequate to promote cross-linking.

The use of various pyridine compounds including 2- pyridine aldazine has been proposed as accelerators for cobalt and other driers in Wheeler Pat. 2,961,331. However, the pyridine aldehydes required to make the azines are expensive. Furthermore, it was considered essential to have the pyridine nucleus present.

It is an object of the present invention to prepare novel trihydrazine cobalt complexes.

Another object is to prepare novel cobalt trihydrazinate hydrochloride complexes.

A further object is to provide novel driers for drying alkyd coating compositions and unsaturated polyesters.

An additional object is to provide a novel procedure for preparing ketone aldol condensations.

It has now been found that these objects can be attained by preparing novel cobalt II halide trihydrazinates of the formula where R is H, alkyl, aralkyl, aryl or haloaryl and X is halogen and the use of these compounds are the known cobalt II dihydrazinates of the formula for curing drying alkyd resins and as curing agents in other oxidative polymerization reactions such as crosslinking of olefin polymer systems, particularly unsaturated polyesters initiated by organic peroxides. The compounds of the present invention are preferably employed as the sole cobalt source in such curing systems, but they can be re placed in part, e.g. up to by conventional cobalt driers, e.g. cobalt Lethylhexoate, cobalt naphthenate, cobalt neodecanoate, cobalt resinate, etc.

The compounds of the present invention of Formulae 1 and 2, as well as the old compounds of Formula 3, are also useful as catalysts in the aldol condensation of ketones.

The compounds of the present invention are extremely sensitive to heat and oxidation and preferably are stored in an inert atmosphere, e.g. nitrogen, helium or argon at a low temperature, e.g. 0 C. Since in many instances the bromides and iodides tend to decompose violently when exposed to air, it is preferred to employ thechlorides.

It has been found that under anhydrous conditions, hydrazines react with 2,2' bipyridyl cobalt (II) halide complexes to form, by ligand. displacement, quantitative amounts of the corresponding cobalt (II) halide trihydrazinate complexes, a typical equation being As stated, many of these new complexes have limited stability, tend to become pyrophoric when exposed to air and sometimes lead to explosive decompositions.

When aryl substituted hydrazines are reacted with cobaltous halides, the formation of the trihydrazinate is hindered by the size of the halogen atom rather than the size of'the aryl group. It is thus easier to prepare the tris (phenyl hydrazine) complex of cobalt (II) chloride than the bromide analog.

' Furthermore, there can be prepared tris(hydrazine hydrochloride) complexes of cobalt (II) halides previously unknown. These chelates have the particular merit of being extremely water soluble and are useful as homogeneous catalysts in that medium.

Cobalt (H) chloride trihydrazinate hydrochloride [[Co(II) (N H -HCl)3]Cl was prepared by reacting benzalhydrazone with hydroxylamine hydrochloride in presence of cobaltous chloride. Beside the desired complex, quantitative amounts of benzaldoxime were isolated:

While not being limited to theory, it is believed that the reason why the excessive stoichiometry is needed in the reaction above is that, in order to obtain the tris hydrazinate hydrochloride, one first forms the unstable hexahydrazinate hydrochloride, an unidcntate complex which, upon ligand displacement, leads to the desired chelate and free hydrazine hydrochloride:

As opposed 'to the well known tetrahedral or planar configuration of the cobalt (II) halide dihydrazinates in which the cobalt is tetracoordi-nate (Fig. 1A), the new trihydrazinates and trihydrazinates-hydrochlorides are believed to have an octahedral Werner configuration with the hexa coordinated cobalt (Fig. lb).

Whether in their anhydrous solid form or in solution in various organic solvents such as ketones, aldehydes, amides, esters, alcohols or amines, the cobalt (II) halide dihydrazinates and, to a higher degree, trihydrazinat-es have been found to be very potent catalysts in various chemical processes involving oxygen transfer reactions. Typical solvents which can be used to dissolve the chelates mentioned. above are: cyclohexanone, benzaldehyde, dimethyl formamide, dimethyl sulfoxide, n-propyl alcohol, propylene glycol, methylacetoacetate, acetic anhydride, N,N, dimethyl aniline, acetone, methyl ethyl ketone, methyl amyl ketone, isophorone, diethyl ketone, 'di-n-propyl ketone, diisopropyl ketone, di-n-butyl ketone, diisobutyl ketone, di-sec-butyl ketone, di-t-butyl ketone, di-n-amyl ketone, methyl-n-propyl ketone, pinacolone, 6-methy1-2- heptanone, methyl n-octyl ketone, ethyl n-butyl ketone, 1- hydroxy-Z-propanone, 3-hydroxy-2-butanone, diacetone alcohol, cyclobutanone, cyclohexanone, Z-methyl cyclohexanone, cycloheptanone, fenchone, acetophenone, benzophenone (molten), biacetyl, acetyl propionyl, acetyl acetone, mesityl oxide, hexanone-3, furfural, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, valeraldehyde, heptaldehyde, glyoxal, o-chlorobenzaldehyde, p-tolualdehyde, salicylaldehyde, phenylacetaldehyde, tetrahydrofurfural, glutaraldehyde, aniline, N,N-diethyl aniline, N-methyl aniline, propyl amine, isopropyl amine, butyl amine, decyl amine, diethyl amine, dipropyl amine, diisobutyl amine, diamyl amine, methyl ethyl amine, triethyl amine, tributyl amine, ethylene diamine, cyclohexyl amine, dicyclohexylamine, o-toluidine p-toluidine, mtoluidine, p-2-xylidene, o-chloroaniline, p-phenetidine, N-ethyl aniline, dimethyl acetamide, isopropyl alcohol, ethyl alcohol, methyl alcohol, butyl alcohol, sec. butyl alcohol, hexyl alcohol, isooctyl alcohol, Z-ethylhexanol, n-octyl alcohol, decyl alcohol, isodecyl alcohol, dodecyl alcohol, ethylene glycol, glycerine, dipropylene glycol, diethylene glycol, mono butyl ether of diethylene glycol, hexamethylene glycol, polyethylene glycol molecular weight average 500, propionic anhydride, ethyl acetate, propyl acetate, amyl acetate, benzyl acetate, butyl acetate, cyclohexyl acetate, phenyl acetate, ethyl propionate, methyl butyrate, amyl valerate, heptyl laurate, ethyl palmitate, diethyl oxalate, dimethyl malonate, dimethyl adipate, diethyl sebacate, butyl lactate, methyl benzoate, ethyl benzoate, dioctyl phthalate, dibutyl phthalate, methyl salicylate, ethyl acetoacetate, phenyl acetoacetate.

In making the compounds of Formula 1, there are employed cobalt II bipyridine complexes such as cobalt (II) bipyridine difluoride, cobalt (II) bipyridine dichloride, cobalt (II) bipyridine dibromide, cobalt (II) bipyridine diiodide. As hydrazines there can be used hydrazine, phenyl hydrazine, p-tolyl hydrazine, methyl hydrazine, allyl hydrazine, isopropyl hydrazine, n-hexade'cyl hydrazine, octadecyl hydrazine, cyclohexyl hydrazine, benzyl hydrazine, Z-naphthyl hydrazine, 2-chlorophenyl hydrazine, phenylethyl hydrazine, 4-bromophenyl hydrazine, 2- fiuorophenyl hydrazine, 2,4-dichlorophenyl hydrazine, octyl hydrazine, p-ethylphenyl hydrazine.

Any desired solvent can be used such as those set forth above.

Examples of compounds Within Formula 1 \(cobal-t al- Ways having a valence of 2) are cobalt tr'ihydrazine dichloride, cobalt t'rihydrazinate difiuoride, cobalt trihydrazinate dibromide, cobalt trihydrazinate diiodide, cobalt tris (phenylhydrazinate) diuoride, cobalt tris (phenylhydrazinate) dichloride, cobalt tris (phenylhydrazinate) dibromide, cobalt tris phenyl hydrazinate) idi iodide, cobalt tris (p-tolyhydrazinate) dichloride, cobalt tris (o tolylhydrainate) dibromide, cobalt tris (methylhydrainate) dichloride, cobalt tris (ethylhydrazinate) dibromide, cobalt tris (allylhydrazinate) dichloride, cobalt tris (isopropyl hydrazinate) dichloride, cobalt tris (n-hexadecyl hydrazin-ate) dichloride, cobalt tris (n-octadecylhydrazinate) dichloride, cobalt tris (cyclohexylhydrazinate) dichloride, cobalt tris (benzylhydrazinate) dichloride, cobalt tris (2- naphthylhydrazinate) dichloride, cobalt tris -(2-chlorophenylhydrazinate) dichloride, cobalt tris (phenylethylhydrazinate) dichloride, cobalt tris (4-bromophenylhydrazinate) dichloride, cobalt tris (Z-fluorophenylhydrazinate) dichloride, cobalt tris (2,4-dichlorophenylhydrazinate) dichloride, cobalt tris (octylhydrazinate) dichloride and cobalt tris (p-ethylphenylhydrazinate) dichloride.

In making the compounds of Formula 2, there are employed cobalt (II) halides such as cobalt (II) fluoride, cobalt (II) chloride, cobalt (II) bromide and cobalt (II) iodide together hydroxylamine hydrochloride, hydroxylamine hydrobromide and hydroxylamine hydroiodide together with a hydrazone. Examples of hydrazones include p-bromoacetophenone hydrazone, acetaldehyde hydrazone, benzal hydrazone, p-methylbenzal hydrazone, o-tolual hydrazone, benzophenone hydrazone, acetophenone hydrazone, valeraldehyde hydrazone, cyclohexanone hydrazone, acetone hydrazone, benzophenone hydrazone, furfural hydrazone, pentanone-3-hydrazone, butanone- 2-hydrazone, heptadecanone 9 hydrazone, pentacosanone-3-hydrazone, isobutyraldehyde hydrazone, nbutyraldehyde hydrazone, propional hydrazone, octaldehyde hydrazone, stearaldehyde hydrazone.

Examples of compounds within Formula 2 (cobalt always having a valence of 2) are cobalt chloride trihydrazinate hydrochloride, cobalt bromide trihydrazinate hydrochloride, cobalt iodide trihydrazinate hydrochloride, cobalt fluoride trihydrazinate hydrochloride, cobalt bromide trihydrazinate hydrobromide, cobalt iodide tt ihydrazinate hydroiodide.

The old cobalt 'II halide dihydrazine complexes within Formula 3 which can also be used as catalysts in the present invention can be made by conventional processes such as those disclosed in Audrieth et al., The Chemistry of Hydrazine (Wiley, 1951), Ahmed et al., Z. Anorg. Chem. Vol. 330, pages 2l02l6 (1964); Nicholls et al., J. Chem. Soc. (A) (1966) pages 950-952; Clemens et al., Inorg. Chem. (1963), Vol. 2, page 1251 and Nicholls et al., J. Chem. Soc. (1964), page 4204.

Examples of compounds within Formula 3 (cobalt always having a valence of 2) are cobalt chloride dihydrazinate, cobalt bromide dihydrazinate, cobalt chloride di(phenylhydrazinate), cobalt bromide di(phenylhydrazinate), cobalt chloride di(methylhydrazinate).

The compound of Formulae 1 and 2 appear to impart faster curing than the comparable compounds of Formula 3.

The polymerization of unsaturated polyesters by a crosslinking process is known to occur by free radical initiation and this is usually achieved by using organic peroxides as polymerization catalysts. While the rate of decomposition of such peroxides into free radicals is influenced by the type of peroxide and the temperature used, it is also directly influenced by the addition of accelerators or inhibitors. Accelerators promote the decomposition of peroxides into free radicals at temperatures below those required to release free radicals if the peroxide is used alone.

When treated with catalyst-accelerator combinations, standard unsaturated polyester resins show various gelation and cure characteristics which depend on the nature of the said combination. During polymerization, resins pass through a critical point at which the viscosity increases suddenly (gel point) then harden slowly while undergoing an exothermic polymerization reaction. Both the gel time and the cure exothermic heat have significant influence on the physical properties of the finished product as well as the practical workability of the resin in various applications.

In the present state of the art, cobaltous carboxylates, such as cobalt naphthenate, are among the most active accelerators available, but their limitations are still numerous and the gel time of a standard polyester resin catalyzed with methyl-ethyl ketone peroxide can merely be shortened by only 50%, with this accelerator. The cure time, expressed in minutes necessary to reach the polymerizations peak exotherm, takes well over the half hour and the performance cannot be improved by merely increasing the metal content of the polymer. We .have found that the di and tri hydrazine cobalt (II) halide complexes described above showed catalytic activity of the order of twenty times that of cobalt carboxylates.

When used with acyl peroxides as primary catalyst these cobalt accelerators have obtained polyester gel times of a few seconds. A further advantageous feature of these accelerators is their versatility as gel-cure modifiers. The variation of the peroxide-accelerator ratio allows a multiple choice in gel times and cure rates of polyester systems following the processors requirements.

Finally, these accelerators reduce considerably the air inhibition encountered in coatings applications where the crosslinking polymerization of thin films is usually affected by the presence of relatively large amounts of oxygen. It was thus possible to cure such thin films to hardness by the mere addition of small amounts of cobalt halide hydrazine complexes as cocatalysts. The effectiveness of the cobalt hydrazine accelerators was observed at usage levels as low as 0.001% by weight of the resin and the accelerators can be used at levels as high as 5% or even 10% (in solution or otherwise), levels at which they cause immediate polymerizations. At higher levels the discoloration of the resin by the catalyst system is undesirable for some uses. Another area of application where cobalt II halide hydrazine complexes constitute a significant improvement over existing art is the drying of paint films. They are particularly useful as primary drying catalysts for long oil alkyd paints which usually require long drying times and relatively high metal concentrations. It is well known that various soaps of cobalt constitute the preferred paint driers as they are most susceptible to promote the autoxidation process by free radical induction at the sites of unsaturation in the paint film. As pointed out before, in the case of unsaturated polyester resins where the new catalysts overcome the air inhibition, the cobalt hydrazine complexes tend to use oxygen itself as a source of free radicals. The superior performance observed earlier was confirmed when ketone solutions of the cobalt hydrazine complexes were used as drying catalysts at similar levels of usage, varying from 0.0001%, usually 0.001% to 5%, or more, e.g. up to.l0%. Furthermore, we have found that the complexes described above show some characters of specificity when used as catalysts for certain aldol condensation reactions. We have found, for instance, that the self-condensation of cyclohexanone catalyzed by the cobalt (II) bromide di hydrazine complex yields quantitative amounts of pure l-cyclohexene-Z- cyclohexanone whereas the same condensation catalyzed with the cobalt (II) chloride analog tends to promote poly condensation leading to extensive amounts of a poly cyclohexene resin.

Mesityl oxide is also obtained very easily and in high yields by self-condensation of acetone catalyzed by various cobalt hydrazine complex catalysts. The amount of catalyst necessary for satisfactory completion of these condensation reactions varies with the nature of the reaction and of the catalyst. In this aldol type of condensation there can be used any of the ketones previously mentioned. The catalyst can be used to provide cobalt in the amount of 0.001 to 10% of the ketone.

Some homogeneous reactions such as the production of polyphenylene oxides can be catalyzed with as little as 1% of a cobalt halide trihydrazine in solution whereas in some heterogeneous conditions as much as 10% of the solid complex may be required. It is apparent from the results obtained, that the novel cobaltous halide trihydrazine complexes as well as the better known dihydrazine analogs constitute a class of highly active catalysts useful in several diverse areas of application.

In the crosslinking of olefinic polymer systems, e.g. unsaturated polyesters, there are included peroxides as is conventional in the art. The peroxide can be 0.05 to 5%, based on the polymer. Examples of suitable peroxides include methyl ethyl ketone peroxide, dicumyl peroxide, benzoyl peroxide, cumene hydroperoxide, di (t-butyl peroxide), m-bis (alpha-t-butylperoxyisopropyl) benzene, methyl isobutyl ketone peroxide, cyclohexanone peroxide, methyl tetrahydrofurane hydroperoxide, bis (4- chlorobenzoyl) peroxide, phthalyl peroxide, dilauroyl peroxide, t-butyl peracetate, diacetyl peroxide, di (2,4- dichlorobenzoyl) peroxide, dipelargonyl peroxide, 3,5-dihydroxy-3,5-dimethyl-1,2-dioxacyclopentane, t-butyl peroxybenzoate, t-butyl peroxy (Z-ethylhexanoate) 0,0-tbutyl O-isopropyl mono peroxycarbonate, 2,5-dimethyl- 2,5-di (benzoylperoxy) hexane, t-butyl peroxy (Z-ethylbutyrate'), 2,5-dimethyl2,5-di (Z-ethylhexanoylperoxy) hexane, di-t-butyl diperoxyphthalate, 0,0-t-butyl hydrogen monoperoxymaleate, n-butyl 4,4-bis (t-butylperoxy) valerate, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, bis-(p-bromobenzoyl) peroxide.

Any of the conventional pigments can be employed in the paints such as titanium dioxide, ferric oxide, calcium oxide, zinc oxide, ochre, litharge, white lead, clays, e.g. kaolin and china clay, calcium carbonate, silica, talc, asbestos, diatomaceous earth, basic lead carbonate, whiting, lithopone, zinc sulfide, antimony trioxide, barium sulfate, red lead, Spanish oxide, burnt sienna, red iron oxide, Venetian red, cadmium red, cadmium sulfoselenide, cadmium-mercury sulfide, raw umber, burnt umber, sienna hydrated yellow iron oxide, chrome yellow, chrome orange, molybdenum orange, zinc chromate, basic zinc chromate, cadmium yellow, chrome green, chromium oxide green, iron blue, ultramarine, blue basic lead sulfate, carbon black, precipitated black iron oxide and metallic pigments, e.g. aluminum powder.

' Conventional paint solvents can be employed such as aromatic and aliphatic hydrocarbons, e.g. benzene, toluene, xylene, aromatic naphtha, mineral spirits, isooctanes, hexane petroleum ether and VM&P naphtha, as well as water for water-based paints.

The drying accelerators of the present invention can be employed with any of the conventional drying alkyd resins and unsaturated polyesters.

The curing alkyd resins can be made from acids (or the anhydrides if available) such as phthalic anhydride, isophthalic acid, trimellitic acid, pyromellitic acid, trimesic acid, maleic anhydride, fumaric acid, azelaic acid, succinic acid, adipic acid, tetrahydrophthalic anhydride, tetrachlorophthalic anhydride, dimerized fatty acids and sebacic acid reacted with polyhydric alcohols such as glycerol, pentaerythritol, dipentaerythritol, trimethylolethane, sorbitol, trimethylolpropane, ethylene glycol, propylene glycol, neopentylene glycol and dipropylene glycol together with drying oils such as soyabean oil, linseed oil, tung oil, dehydrated castor oil, fish oil, corn oil, perilla oil, safilower oil, oiticica oil and cottonseed oil, as well as the acids of such drying oils and tall oil acids.

Unless otherwise indicated, all parts and percentages are by weight.

Typical suitable unsaturated oil or fatty acid modified alkyd resins are set forth below. They can have oil lengths of 30 to 70 or even higher.

Parts Alkyd A Alkyd B Tall oil fatty acids Soybean oil 140. 0

Pentaerythritol 98% glycerol- 90. 0 Ethylene glycoL. Phthlaio anhydnde. 145. 0 Maleic anhydride. 3. 0

Acid Number Alkyd E Alkyd F Soyabean oil 132. 0 175 0 Linseed oil 132. 0 1 50. 0 0. 09 0. 91.0 83. 0 148. 0 145. 0 Maleic anhydride. 3. 0 Acid Number 12 8 TABLE-Continued Parts Alkyd G Alkyd 11 Tall oil fatty acids 322. 0 230. 0

98% glycerol Phthalic anhydn'de Isophthalic acid Maleic anhydride.

Acid Number 10 12 Alkyd K Alkyd L Tall oil fatty acids 719. O 1, 740. 0

Pentaerythritol 173. 0 284. O

Isophthalic acid 166. 0 166. 0

Acid Number 1O 12 Alkyd M Alkyd N Linseed oil 700. 0

Safllower oiL 1, 180. 0

Pentaerythntol Phthalic anhydride Isophthalic acid Acid Number Typical examples of unsaturated polyesters, polyester resins are set forth below. In polyesters A through I, the

acid and alcohol components prereacted to the indicated acid number were dissolved in styrene to give 70% total nonvolatiles, i.e. the styrene was 30% of the composition. The final compositions also contained 0.015% of t-butyl catechol.

Parts Polyester A Polyester B 1,2-propylene glycol 1, 700 1, 700 Maleic anhydride. 1, 528 1, 528 770 770 0. 40 0. 40 72 31. 4 Styrene (1) 1 Polyester 0 Polyester D Polyester E 1,2-propylene glycol 1, 700 1, 700 1, 700 Fnmanc acid 1, 810 603 1, 810 Isophthalie acid S64 Phthalic acid- 770 2, 309 Hydroquinone 0. 42 0. 46 O. Acid Number- 37. 1 26. 6 30. 3 Styrene Polyester F Polyester G 1,2propylene glycol 1, 700 1, 370 Fumarle acid 1, 447 1, 170 Adipic acid. 1, 095 HET acid.-. 2, 355 Phthalic anhydride 126 110 Hydroquinone 0. 44 0. 5 Acid Numbeiz 11. 7 46. 7 Styrene Polyester H Polyester I Diethylene glycol 233. 4 292. 0 Ethylene glycol 170.0 Maleic anhydrlde. 196. 1 343. 0 Phthalic anhydride 111. 0 Adipic acid. 109. O p-iaButyl cateehol. 0. O2 0. ()2 Acid Number- 45 25 Styrene 1 39% of composition.

As is conventional in the art, the styrene can be 20 to of the total composition. In place of styrene, there can be used other ethylenically unsaturated compounds such as diallyl phthalate, triallyl isocyanurate, acrylamide, N-t-butylacrylamide, triallyl cyanurate, p-vinyl toluene, acrylonitrile, alpha methyl styrene, divinyl benzene, N- vinyl pyrrolidone, methyl acrylate, methyl methacrylate, allyl diglycol carbonate, trimethylolpropane diallyl ether,

trimethylolpropane monoallyl ether, allyl ethers of sorbitol, pentaerythritol, sucrose and glucose. Any of the polybasic acids and polyhydric alcohols employed in making alkyd resins can be incorporated as components in making the unsaturated polyester resins.

1 Phenyl hydrazine was clgsen as the standard substituted hydrazine in the preparations and it was found that even the relatively large size of the aromatic ring did not prevent the formation of the octahedral complex Water thinnable unsaturated polyester formulations 5 With Cobalt II chloride.

TABLE 1 Analysis Calculated Found N H 01 00 N H 01 [Co(II)(N H ]Cl 26.1 37.1 5.3 31.4 26. 04 a4. 95 5.1 31.4 Infra-red spectra 3,195 VS, 3,090 VS, 2,175 w, 1,620 VS, 1,590 vs, 1,400 5, 1,310 5,

1,220 s, 1,160 vs, 9 0 s, 620 m, 665 vs, 518 m.

[Co(II)(CgH -NH-NH9 Cl 13.0 18.5 5.3 15.6 10.81 18.6 6.08 13.1

1 Carbon: Calculated-47.7%; found48.8%.

can be used, e.g. those shown in Ghosh Pat. 3,463,750 (the entire disclosure of Ghosh is incorporated by reference). A typical formula is that shown in Ghosh Example 1 made from 108 parts trimellitic anhydride, 118 parts phthalic anhydride, 108 parts trimethylolpropane and 269 parts trimethylolpropane-diallyl ether having an acid No. of 50-52 and dissolved in parts isopropanol, 60 parts of 28% aqueous ammonia, 390 parts of water and 90 parts t-butyl alcohol. This solution at solids is hereinafter called Polyester Formulation I.

The following examples illustrate the preparation of the novel compounds of the present invention, their use as promoters for ketone aldol condensation reactions and the advantages of drying alkyd paint and varnish compositions and unsaturated polyester formulations containing the acceleartors and catalysts of the present invention.

The standard procedure for evaluating films was the determination of time until the film was dust free and thorough hard. These times were determined in the following manner. Within 24 to 48 hours after preparation of the formulation, a film was applied on a polished plate glass panel by means of a 0.006 inch Bird applicator delivering a Wet film thickness of 0.003 inch. The film was allowed to dry in an environmental room at constant temperature and humidity, illuminated by artificial light and allowing 95% reproducibility. The drying times of the film were determined by the improved Gardner circular drying time recorder over a period of 24 hours. The recorder basically consists of a synchronous motor with its shaft oriented in the true vertical. A pivotable arm assembly is attached to this shaft and operates a counterpoised vertical stylus consisting of a thermosetting Teflon sphere which does not stick to the drying film. When the stylus, set in motion by the motor, no longer leaves a clear channel but begins to rupture the dry upper layer of the film, the surface may be considered to be dust free. When the stylus no longer ruptures the film but moves freely on its surface, the film may be considered thorough hard.

EXAMPLE 1 Cobalt II halides trihydrazine complexes were prepared by the following general procedure: 0.02 mole of cobalt II halide 2,2-bipyridine complex or cobalt II halide azine complex was dissolved in 50 g. of dimethyl formamide. To this solution was added under strong agitation and under exclusion of air 0.06 mole of anhydrous hydrazine diluted in 50 g. of dimethyl formamide. The reaction product precipitated readily, was filtered and dried in vacuo. The dry trihydrazine complexes are unstable when exposed to air but can be stored in ampoules under nitrogen. Table 1 summarizes several preparations of such complexes and reports the analytical data relevant to those of the compounds which could be handled safely. All compounds were spectrographed in the infrared on a Perkins Elmer InfracordModel 337 by means of KBr water. All spectra showed a medium to strong absorption band at 970 cm. characteristic of the bidentate character of the hydrazine ligand.

The cobalt II trihydrazinate dichloride was prepared using as reactants 0.02 mole of cobalt II, 2,2-bipyridine dichloride complex and 0.06 mole of anhydrous hydrazine in the manner indicated supra. [It was also prepared by dissolving 6.4 grams (0.02 mole) of (cyclohexanone azine) cobalt II chloride in 50 ml. of dimethyl formamide and adding thereto, under strong agitation, a solution of 3.0 grams of anhydrous hydrazine in 50 ml. of dimethyl formamide. The immediately formed pale orange precipitate was filtered and washed with anhydrous ether. The cobalt II trihydrazinate dichloride was obtained in quantitative yields and analyzed Co 26,04; Cl 31.4%, N 33.0%, H, 5.01%. (The starting cyclohexanone azine) cobalt II chloride was prepared by adding as solution of 0.1 mole of anhydrous cobalt II chloride in 50 ml. of dry acetone, slowly, under agitation to a solution of 19.2 grams (0.1 mole) of cyclohexanone azine in 50 ml. of dry acetone at room temperature and collecting precipitate which formed] While the cobalt II trihydrazinate dichloride is unstable in air and can decompose violently, it can be stored in ampoules under nitrogen and kept refrigerated for several days.

The cobalt II tri(phenylhydrazinate) dichloride was obtained in quantitative yields by reacting a solution of 6.4 grams (0.02 mole) of (cyclohexanoneazine) cobalt II chloride in 50 ml. of dimethyl formamide with 9.1 grams of phenylhydrazine. It was salmon pink in color and unstable in air but less explosive than the tris hydrazinates.

Cobalt II trihydrazinate dibromide UD 2 4)a1 "2 and cobalt II trihydrazinate diiodide were prepared by the procedure outlined above but could not be analyzed because of their tendency to decompose violently in air. Infra-red spectrography, however, confirmed the bidentate character of this ligand.

EXAMPLE 2 51 grams of cobalt 'II dihydrazinate dichloride (a known compound) was prepared from cobaltous chloride and hydrazine hydrate Was prepared by conventional procedure and suspended in 414 grams of cyclohexanone and refluxed for two hours until the reflux temperature reached -195 C. Atthis point the complex was in solution in a mixture of cyclohexanone and cyclohexanone aldol polycondensation products. This solution contained approximately 4% cobalt and was useful as an active catalyst in curing drying oil modified alkyd resins and as an activator for a crosslinkable unsaturated polyester resin.

When the refluxing is continued for several more hours above 200 C., extensive polycondensation of the cyclohexanone occurs and polycyclohexene can be precipitated by addition of hexane to the reaction mixture. The polymer was characterized by infra-red analysis.

1 1 EXAMPLE 3 2.5 g. of cobalt II bromide dihydrazine complex [Co(II)(N H ]Br was suspended in 250 g. of cyclohexanone and the reaction mixture was refluxed for 3 hours until the reflux temperature reached 275 C. and 23 g. of water had been'eliminated. The final product was distilled under vacuum to yield 184 g. of pure l-cyclohexene-Z-cyclohexanone (81% theory) characterized by elemental analysis, infra-red analysis and physical properties.

EXAMPLE 4 The polymerization of 50 g. of Laminac 4152 (a styrene modified rigid polyester resin of low reactivity and of medium molecular weight, viscosity 4-5 poises at 77 C., manufactured by the American Cyanamid Co.), was initiated by the addition of 0.5 g. of methyl ethyl ketone peroxide and 0.5 g. of a 6% (as cobalt metal) solution of the respective cobalt II halide hydrazine complexes of Table 2 in cyclohexanone.

The gel time for each sample was determined at 22 C. on a comparative viscosimeter capable of measuring the length of timerequired to reach the point of gelation. The cure time and peak exotherm were determined on a West single pen recording potentiometer. One sample was accelerated with 0.5 g. of cobaltous naphthenate (6% Co) and used as a control.

In place of the Laminac 4152 in Example 4, the use of Polyester A gives similar results.

EXAMPLE 5 The experiment of Example 4 was repeated using very low levels of the catalyst-accelerator system at 22 C. The 50 g. of Laminac 4152 resin containing 0.05 g. of tertiary butyl hydroperoxide and 0.1 g. of a benzaldehyde solution of cobalt II chloride dihydrazine complex [Co(II) (N H ]Cl (6% Co) gelled in 16 minutes and cured in 105 minutes whereas under similar conditions the resin containing 0.1 g. of cobalt naphthenate (6% Co) instead of the hydrazine complex had a gel time of several hours and did not cure after several days. Similar results are obtained where Polyester A is substituted for the Laminac 4152.

EXAMPLE 6 50 g. of OX 5 86, a high molecular weight, low reactivity styrene modified polyester resin manufactured by the Chevron Chemical C0,, was catalyzed at 22 C. with 0.5 g. of benzoyl peroxide and 0.5 g. of cobalt (H) chloride dihydrazinate (6% Co) in solution in dimethyl acetamide to give a cured resin in a short period of time. Similar results are obtained when Polyester I is substituted for the CX 586.

EXAMPLE 7 0.5 g. of cobalt (II) chloride trihydrazinate was suspended and dispersed in 50 g. of Laminac 4152 resin. 0.5 g. of benzoyl peroxide was then added to the system and the gel time and cure time were determined as in Example 4. A gel time of 2 hours and a cure of 4 hours was obtained whereas a similar resin containing the peroxide but no accelerator could not gel nor cure after 24 hours.

The dihydrazinate analog led respectively to a gel time of 3 hours and a cure time of 5 hours as shown in Table 3.

Similar results are obtained when Polyester A is substituted for Laminac 4152.

EXAMPLE 8 A typical long oil alkyd test formulation was prepared consisting of (a) a grind containing 1265 g. of titanium dioxide, 1000 g. of 505-70 alkyd resin (a pure soya based long oil alkyd resin having about 63% soya oil and 23% phthalic anhydride, Acid No. 10 maximum, manufactured by the McCloskey Varnish Co.), 115 g. of Rule 66 Mineral Spirit and (b) a let down containing 1145 g. of the same 505-70 alkyd vehicle and 500 g. of the same Rule 66 solvent. To g. of the above composition was added 0.05 g. of methyl ethyl ketoxime as an antiskinning agent, and 0.4 g. of a cyclohexanone solution of the respective cobalt halide hydrazine complexes reported in Table 4. (The solutions were standardized at a 6% cobalt content.) All systems were evaluated under the standard procedure set forth above, at a room temperature of 32 C. and 30% humidity and compared to two similar systems, one containing 0.4 g. of cobalt octoate (6% Co) as drier, the other containing no drier. The results are summarized in Table 4.

TABLE 4 Through hardness,

Dust free,

hours Drying catalysts hours [0001) (NzHDaHz 9 [00(11) (NqHOslClr 3 20 (N 2 02] 2 3 G 2 021011 powder Wet Cobalt octate No catalyst Wet 1 0.08 g. of solid was used, prorated for a metal content equivalent to that of the other systems.

The powdered cobalt II dihydrazinate dichloride did not perform as well as the solution because it decomposed upon standing in air.

In place of the 505- alkyd resin in Example 8, the same amount of Alkyd I gives similar results.

EXAMPLE 9 The drying of 50 g. of the basic formulation of Example 8 but containing no titanium dioxide pigment and no antiskinning agent was catalyzed by the addition of 0.4 g. of acetic anhydride solution (6% Co) of the two cobalt-hydrazine complexes reported in Table 5 and these systems were compared to an uncatalyzed system.

TABLE 5 Through Dust; free, hardness, Catalysts hours hours No catalyst Wet Wet [00(11) (C6H5NHNH2)2]BH 2. 5 14 [00(II) (CH5NHNH) [a 22 24 In place of the 505-70 alkyd resin in Example 9, there can be used the same amount of Alkyd H with similar results.

EXAMPLE 10 (6% Co) instead of the cobalt naphthenate was able to dry in less than 24 hours, the accelerator having overcome the air inhibition process observed with the prior formulation. Furthermore, the same Laminac resin (50 g.) containing [Co(II)(N -H ]Cl as sole catalyst (1.0 g. 6% Co) (no .peroxide) dried Within 48 hours, thus showing the ability of the cobalt halide hydrazine complex to initiate free radical formations by using the atmospheric oxygen as a source.

In place of the Laminac resin, Polyester A can be used with similar results.

EXAMPLE 11 41.4 grams (0.6 mole) of hydroxylamine hydrochloride were dissolved in a solution of 13 grams (0.1 mole) of cobaltous chloride in 250 ml. of methanol. To this solution was added, dropwise, under agitation and at room temperature, 69 grams (0.6 mole) of freshly distilled benzalhydrazone. The agitation was maintained for 30 minutes and the precipitated purple complex was filtered, washed with ether and air dried. 33 grams of tris (hydrazine hydrochloride) cobalt II chloride of the formula [N H -HCl) Oo(II)Cl was obtained (99% yield). The product was stable in air and very soluble in water. Quantitative amounts of benzaldehyde and residual hydrazine hydrochloride were isolated by distillation of the methanol filtrate.

The analysis of the tris(hydrazine hydrochloride) cobalt (II) chloride was Co 17.6% (theory 17.6%), C1 52.5% (theory 52.4%), N 24.9% (theory 25.1%), H 4.4% (theory 4.5%

What is claimed is:

1. Cobalt II halide trihydrazinates having one of the formulae where R is H and X is halogen.

2. A compound according to claim 1 having Formula 1.

3. A compound according to claim 2 where X is Cl, Br or I.

4. A compound according to claim 3 where X is chlorme.

5. A compound according to claim 1 having Formula 2.

6. A compound according to claim wherein all Xs are chlorine.

14 7. A process for making a compound of claim 5 comprising reacting a hydrazone with hydroxylamine hydrohalide in the presence of cobalt II halide.

8. A process according to claim 7 wherein all halogens are chlorine.

9. A process for making a compound of claim 2 comprising reacting an anhydrous hydrazine of the formula RNHNH with cobalt II halide bipyridine complex. 10. A composition comprising (a) a compound having one of the formulae UNITED STATES PATENTS 910,858 1/1909 Raschig 23190 R 3,1'89,411 6/ 1965 Kohnen et al. 23--1'90 R 3,258,478 6/1966 Baum 2319O R 3,429,920 2/1969 De ROOij 23-190 R OTHER REFERENCES Linke et al.: Z. fiir Anorg. and Allge. Chemie, vol. 356, February 1968, pp. 113 117.

OSCAR R. VERTIZ, Primary Examiner H. S. MILLER, Assistant Examiner U.S. Cl. X.R. 423466 

